1. Field of the Invention
The present invention relates generally to pipettes, and more particularly to a single-piece inexpensive, disposable volumetric dispensing pipette which delivers a precise, reproducible volumetric quantity of liquid.
2. Discussion of the Prior Art
Various types of devices are known for dispensing a volumetric quantity of liquid, such as standard glass and plastic pasteur pipettes, serological pipettes, calibrated capillary tubes, conventional medicine or eye droppers, air and positive displacement pipettes and syringes. These devices are, for the most part, inaccurate or expensive to manufacture.
U.S. Pat. No. 4,563,104, issued to the present inventor, discloses an improved, high-accuracy liquid dispensing pipette which delivers uniform drops of liquid of given sizes.
Other patents of which the present inventor is aware and which comprise the most pertinent art known to the inventor are British Patent Specification No. 1,031,641; U.S. Pat. Nos. D250,599 and D260,434 issued to the present inventor; U.S. Pat. No. RE 31,555 issued to Garren, U.S. Pat. No. 4,212,204 issued to the present inventor, U.S. Pat. No. 3,748,909 issued to Kuo, and U.S. Pat. No. 3,938,909 issued to Rodrigues.
A drawback common to all prior art pipettes of an inexpensive, disposable type is their inability to reproducibly deliver precise volumetric quantities of liquid. As will be appreciated from the discussion which follows, the improved pipette of the present invention uniquely overcomes this drawback and provides an inexpensive, blow-molded, single piece device capable of dispensing extremely accurate volumes of liquid.